+Res res_open (const char *name);
+void res_close (Res r);
+char *res_get (Res r, const char *name);
+char *res_get_def (Res r, const char *name, char *def);
+void res_put (Res r, const char *name, const char *value);
+void res_trav (Res r, const char *prefix,
+ void (*f)(const char *name, const char *value));
+int res_write (Res r);